U.S. District Judge Robert Hinkle, sitting in Tallahassee, ruled that the 2008 voter-approved measure defining marriage as only between one man and one woman violated the Constitution's guarantees of equal protection and due process.

"The founders of this nation said in the preamble to the United States Constitution that a goal was to secure the blessings of liberty to themselves and their posterity. Liberty has come more slowly for some than for others," he wrote in a 33-page opinion covering two cases, noting that it took the Supreme Court 200 years to invalidate laws prohibiting interracial marriage.

"When observers look back 50 years from now, the arguments supporting Florida's ban on same-sexmarriage, though just as sincerely held, will again seem an obvious pretext for discrimination. Observers who are not now of age will wonder just how those views could have been held," Hinkle declared.

The ruling, which also applies to same-sex marriages performed in other states, followed similar decisions by Florida judges in four counties. The state attorney general has appealed those decisions and will challenge Hinkle's order.

"I am overjoyed that the state we made our home in will soon recognize that what Carol and I had was marriage," said Arlene Goldberg of Fort Myers, one of the plaintiffs in a lawsuit filed in March by the American Civil Liberties Union of Florida. She and her partner of 47 years, Carol Goldwasser, married in New York in 2011; Goldwasser died days after the suit was filed.

The Florida ACLU added Goldberg to the suit after filing on behalf of eight other married same-sex couples and SAVE, the largest LGBT organization in South Florida.

"We are thrilled that these loving and committed couples will soon have the same protections and security for their families that other married couples have," said ACLU attorney Daniel Tilley. "Florida's refusal to recognize their marriages serves no legitimate purpose and is hurtful to Florida families. We're very pleased to see the ban held unconstitutional in such unequivocal terms so that all Florida families will soon finally have the same protections."

In a friend-of-the-court brief supporting the state's ban, the Florida Conference of Catholic Bishops argued it "has a strong interest in protecting the traditional institution of husband-wife marriage because of the religious beliefs of its members and due to this institution's benefits to children, families and society."

In a statement, the bishops said they were "sadly disappointed by the court's decision to reject marriage as the union of only one man and one woman as husband and wife." They argued the decision "fails to adequately consider that marriage unites a man and a woman with any children born from their union and protects a child's right to both a mother and a father."

The bishops said their belief in heterosexual marriage "is not motivated by unjust discrimination or animosity toward anyone. Human dignity is manifested in all persons; and all have the capacity for and are deserving of love. This is especially true of children, who should be given the opportunity, to the greatest extent possible, to be raised and loved by the mother and father who conceived them."

Hinkle issued his opinion in Brenner v. Scott and Grimsley v. Scott a day after the U.S. Supreme Court intervened to prevent same-sex couples from marrying in Virginia after a federal appeals court struck down the state's voter-approved ban in July.

Attorneys general in Virginia, Utah and Oklahoma have asked the justice to pass final judgment on whether states can prohibit same-sex couples from marrying.

Since the Supreme Court struck down a portion of the Defense of Marriage Act last year, 20 federal courts have ruled that bans on same-sex marriage are unconstitutional, Hinkle noted.

"Based on these decisions, gays and lesbians, like all other adults, may choose a life partner anddignify the relationship through marriage," he wrote. "To paraphrase a civil rights leader from the age when interracial marriage was first struck down, the arc of history is long, but it bends toward justice."

Same-sex marriage is legal in 19 states and the District of Columbia.

More than 70 court challenges have been filed in 30 of 31 states, plus Puerto Rico, where same-sex marriage has been outlawed. Five federal appeal courts are reviewing cases from 11 states.